Air conditioning system



J1me 1940- w. H. CARRIER 2,202,946

' AIR CONDITIONING SYSTEM Filed April 18, 1955 I a Q) lNVEN'i'OR 5% r V -M M ATTORNEY Patented June 4, 1940 UNITED STATES PATENT OFFICE Am CONDITIONING SYSTEM Willis H. Carrier, Esse'x Fells, N. J.

Application April 18, 1935, Serial No. 16,992

9 Claims. (01. 257-2) This invention relates to air conditioning for human comfort and more particularly to a method of producing and maintaining desired con- .ditions of temperature and humidity in an en- 5 closure regardless of unforseen and unpredictable variations in heat load afiecting the enclosure.

The disclosure herein was originally set forth in substance in application Serial No. 675,177,

filed June 10, 1933, which, in part, resulted in 7 10 Patent No. 1,956,707, issued May 1, 1934.

The general object of the invention is to pro vide a system of air conditioning in which a plurality of cooling coils are utilized in a dehumidifier, each of the coils serving a predetermined area, lengthwise, crosswise and in depth,

of the dehumidifier, all' of the coils being individually controllable. Another object of the invention is to provide a system of air conditioning in which a plurality of coils are employed in a dehumidifier, no one of which extends wholly across a cross-sectional area of the dehumidifier, the admission of refrigerant to the coils being controlled responsive to requirements of a conditioned area, the temperature of such refrigerant also being controlled in accordance with requirements of a conditioned area.

Another object is to provide a system of-air conditioning in which the area of active heat exchanger surface and the temperature of said surface is individually and/or simultaneously controlled, all said surface being positioned in a dehumidifier through which all air, serving a conditioned area, is passed.

A further object is to provide a series of coils in a dehumidifier, so arranged with respect to outdoor air and return air inlets, that stratifica tion of outdoor and return air passing through the dehumidifier will result, diiferent of the 40 coils being employed selectively to afiect thecondition of said diiferent streams of air.

A feature of the-invention residesin the provision of a source ofi conditioning fluid, a series of cooling coils in a dehumidifier, and controls 4-5 responsive to heat load conditions. inan envided in the dehumidifier.

plurality of coils, no one of which extends across a cross-sectional area of a dehumidifier, whereby a stream of air passing through the dehumidifier ,will be dehumidified in part but emerge from the dehumidifier at a final temperature and relative humidity difierent than that of the dehumidified portion and suitable for introduction into an area employed for human occupancy.

Other objects and features will be more apparent from the following description of the invention to be read in connection with the accompanying drawing, in which aldiagrammatic plan view of an air conditioning system for carrying out the invention is illustrated.

Referring to the drawing, numeral 6 designates a dehumidifier provided with an outside air inlet I having damper 2 therein and a return air inlet 4 with damper 5. The outdoor air and/or return air, depending upon the setting of dampers 2 and 5, will enter chamber 3 at the entrance end of the dehumidifier. Six sections of coils, or heat exchange surfaces, A, B, C, DE and F, are pro- They may be of any desired type, such as plate surfaces, pipes, finned tubing, or other forms of surface, all of which are intended to be included and designated by the numeral 20-. While each ofthe, coils is shown identical in size, they may beof different sizes with respect to one another and of difierent capacities. Fan 7 discharges the air from dehumidifier 6 into enclosure 8, and also serves to draw air into'the dehumidifier from return duct 4 and the outside air connection. Refrigerant or conditioning medium is admitted to coils A, B, C, D, E and F under control of valves 9, Ni, ii, l2, l3 and M respectively. The operation of the valves may be accomplished manually or, preferably, they will be controlled thermostatically responsive to the operation of thermostat I9, located in return duct 4, and hence, responsive to changing heat load conditions in the enclosure. The valves may be normally closed and open under different pressures. For example, valve 9 may be set to open at a pressure of 13 pounds,

' whereas it opens at 11 pounds, i l at 9 pounds,

air will always be subject to the action of one Or'more effective coils. The return air will in great measure pass to the fan above the lower coils, with the result that return air will not be subject to active coils unless load conditions in the enclosure demand cutting into service of at least coil El. Of course, under rising load conditions, if the three lower coils are inadequate to maintain desired conditions in the enclosure, coil C will additionally, be cut in, and if more conditioning is still required, coils B, and then A- will be cut into service.

The stratification arrangement enables the use of return air, untreated, whenever load conditions may adequately be taken care of by the use .of the lower coils alone. In such event, the return air will remain untreated and serve to reheat the air cooled and dehumidified by the lower coils. The dehumidified'air, alone, is at a temperature too cold for comfort, but when mixed with the substantially untreated return air, will form a mixture at a temperature higher than that of the dehumidified air, and at a relative humidity lower than that of the dehumidified air and suitable for introductioninto the enclosure.

When load conditions in the enclosure require the admission of refrigerant to one or more of the upper coils, the return air will be dehumidified in part, but the surface area is so designed that not all of the air will be dehumidified or reduced in temperature below a desired dewpoint.

W'hile coils A-F are arranged so that F becomes active first and is then followed by E, D, etc., it is obvious that the valves may be adjusted to function so that they will open and close in any-desired order. For example, it may be desirable to have F become operative first, then D, then E, then B, and finally D and A. Or, it may be desirable to have F and C become operative together, to be followed in succession by E, D, B and A. No reservation ismade with respect to theorder in which the valves will operate in order to cut the coils in and out of service. Refrigerant may be supplied from a cooler is, served by compressor 23 and condenser 26. A three-way valve l6 may be employed, operative responsive to wet bulb thermostat or hygrostat 2i, positioned in return duct 43. Thus, pump 22 will suppy varying proportions of refrigerated fiuid from cooler l5 and return fluid from the coils, depending upon the setting of valve I 6, the mixture of fresh and return fluid being supplied through pipe IT to the coils. The wet bulb thermostat or hygrostat 2|, as the case may he, therefore, responds to changes in humidity load conditions in the enclosure and supplies colder or warmer fluid to the coils to efiect' more or less dehumidificatlon.

'Zt is obviousthat the coils may be arranged to cut in and out in order to take advantage of the counterflow principle of heat exchange between the air stream and the coils.

Since certain changes in carrying out the above method of operation and in the constructions set forth, which embody the invention, may be made without departing from its scope, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. A method of conditioning air consisting inpassing a stream of air through a conditioner, circulating refrigerant through different sections of one portion of the conditioner, varyingthe number of different sections through which refrigerant is circulated in accordance with air conditioning requirements in an enclosure served by the conditioner, circulating refrigerant azoaaac through different sections of another portion of the conditioner, varying the number of said different sections through which refrigerant is circulated in accordance with air conditioning requirements in the enclosure served by the conditioner, different portions of the air stream passing through said difierent portions of the conditioner and being in indirect heat exchange relation with the refrigerant, and discharging the air stream into the enclosure.

2. A method of conditioning air consisting in passing a stream of air from one source through one part of a conditioner, passing a stream of air from another source through another part of the conditioner, subjecting each stream to the action of a different series of heat exchanger elements, individually controlling the temperature of different elements of each series, and discharging both streams of air, subsequent to their passage through the conditioner into an enclosure served by the conditioner.

3. A system of air conditioning for an enclosure comprising a conditioner, a series of heat exchanger surfaces in one section of the conditioner, another series of heat exchanger surfaces in another section of the conditioner, none of the surfaces extending wholly across a crosssectional area of the conditioner, means for circulating refrigerant selectively through different surfaces of each of said series in accordance with changes in atmospheric conditions in an enclosure served by the conditioner, and means for passing air through the conditioner and discharging it into the enclosure.

4. An air conditioning system comprising aconditioner, an outdoor inlet and a return air inlet connecting to the conditioner, means for drawing air into the conditioner through said inlets and discharging the air subsequent to conditioning into an enclosure served by the conditioner, a first series of heat exchanger surfaces in the path of the return air, a second series of other heat exchanger surfaces in the path of the outdoor air, and means for selectively feeding-conditioning fluid to different heat exchanger surfaces of each of said series responsive to air conditions in the enclosure whereby the number of surfaces to which fluid is fed will vary with heat load conditions in the enclosure.

5. A system of air conditioning for an enclosure comprisinga plurality of heat exchanger surfaces in a first portion of a conditioner, a similar number of heat exchanger surfaces in a second portion of the conditioner, means for selectively feeding refrigerant to individual of the surfaces so that all of thesurfaces in the first portion of the conditioner will first become active before refrigerant is fed to the surfaces in the second portion, and means for passing a stream of air through the conditioner in contact with the surfaces and discharging it into the enclosure, different portions of the air stream passing through said difierent portions of the conditioner.

6. A system of air conditioning for an enclosure comprising a. conditioner, a series of heat exchanger surfaces in one section of the conditloner, aseries of heat exchanger surfaces in another section of the conditioner, none of the surfaces extending wholly across a cross-sectional area of the conditioner, means for circulating refrigerant selectively through individual of said surfaces, and means for passing air through the conditioner and discharging it into an enclosure.

7. A method of air conditioning consisting in causing air to flow in a stream, bringing one porbe conditioned.

portion of the air tion of the air stream into contact-with a series of heat exchange surfaces, bringing another portion of the air stream into contact with a separate series of heat exchange surfaces, selectively supplying conditioning medium to different of the surfaces of each of said series, and delivering both portions of the airstream to an area-to 8. A method of air conditioning consisting in causing air to flow in a stream, bringing one stream into contact with a series of heat exchange surfaces, bringing another portion .of the air stream into contact with a separate seriesof heat exchange surfaces, selectively supplying conditioning medium to individual of said surfaces in accordance with the air conditioning requirements of the area to be conditioned, and delivering both portions of the air stream to said area.

9. Amethod of air conditioning consisting in causing air to flow in a stream, bringing one portion of the air stream into contact with a series of heat exchange surfaces, bringing another portion of the air stream into contact with a separate series of heat exchange surfaces, selectively supplying conditioning medium to individual of 'said surfaces, and delivering both portions of the air stream to an area to be conditioned.

WILL-1s 11. 6mm. 

